Gilalite , Kinoite , Hydroxyapophyllite-(K) Locality: Christmas Mine (Red Bird shafts; Inspiration Mine; Hackberry shafts), Christmas, Christmas area, Banner District, Dripping Spring Mts, Gila Co., Arizona, USA Dimensions: 5.2 x 4.1 x 1.8 cm Description: Gilalite is a very rare hydrated copper silicate found at only four localities worldwide and the Christmas Mine is the Type Locality. Clusters of pretty spring-green gilalite botryoids, bright azure-blue crystals of the rare calcium copper silicate, kinoite and glassy colorless apophyllite crystals are richly scattered on the matrix plate on this very fine and showy combination miniature from this locale. Choice and rare combination material. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Gilalite
A hydrated copper silicate occurring as fracture fillings and incrustations in calc-silicate skarns.
Intro adapted from Wikipedia (CC BY-SA).
Gilalite is an IMA-recognized mineral species in the silicate class, with the chemical formula Cu₅Si₆O₁₇·7H₂O.
It crystallizes in the monoclinic crystal system.
Key properties: Mohs hardness 2; specific gravity 2.72; Nonmetallic luster; optically biaxial.
IMA symbol Gil, IMA status: approved, named in 1979.
A retrograde metamorphic or mesogene mineral formed at the expense of a prograde calc-silicate and sulfide assemblage; in tactites, commonly incrusting fractures; also filling cracks or interstices in diopside grains (Christmas, Arizona.
It is found associated with Kinoite, apachite, stringhamite, junitoite, clinohedrite, xonotlite, diopside, apophyllite, calcite, tobermorite (Christmas, Arizona, USA).
The name refers to Gila Co., Arizona, USA, where it was found.